Flexible shaft



H. TROEGER ETAL 2,647,380

FLEXIBLE SHAFT Aug. 4, 1953 Filed June 24, 1949 2 Sheets-Sheet 1 N INVE NTORS HENRY TROEGE R BERNARD M. GOLDBERG ATTOR NEY 1953 H. TROEGER ETAL 2,647,380

FLEXIBLE SHAFT 7 Filed June 24, 1949 2 Sheets-Sheet 2 FIG. 3

INVENTORS HENRY T/POEGER BERNARD w. GOLDBERG ATTOR NE Patented Aug. 4, 1953 UNITEDLESTATES ATE OFFICE FLEXlBLE si AF'r Henry Troeger, Ramsey, and Bernard'W. Goldberg, Passaic; N. J assign'ors to Bendix Aviation Corporation, Teterboro, N .L, a corporation of Delaware Application are 24; 1949, "Serial No. 101.223

Another object is to provide an improved flex-- ible coupling permitting axial deflection.

Another object is to provide a that will fail safe.

Another object is to provide a flexible coupling in which shaft whip is minimized.

Another object is to provide a universal drive shaft which is particularly suited to the transmission of torque at high speed undermisalighment and vibration conditions encountered inaircraft or similar installations. I

The above and other objects and featuresfiof the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawings wherein one embodiment of the invention is illustrated by way of example.

In the drawings:

Figure 1 is a longitudinal cross section view of 4 a coupling embodying the invention. I I

Figure 2 is a sectional view of a flexible diaphragm utilized in the invention.

Figure 3 is an exploded View of'the coupling illustrated in Figure 1., Referring to the drawings wherein like reference characters indicate like parts in the figures;

there is shown in Figures 1 and 3, a flexible coupling comprising, ingeneral, a driving member I0, a driven member II a quill sshaft I2, and a pair of flexible diaphragm assemblies I3 and M for connecting the members l0 and H to the respective ends of the shaft |2.

The members l0 and II as illustrated are similar. Each has a flange l5 adapted to be secured to mating members of driving and driven elements (not shown), a tubular section l6 and a circumferential flange One end of the diaphragm assemblies l3 and i4 is fastened to the respective flanges ll of the members In and II by means of screws l8 and nuts IS.

The diaphragm assemblies l3 and I 4 each comprises a plurality of substantially annular U-shaped members 20. The diaphragm memflexible coupling 2 Claims. (01. 64 1s) bars 20 have dual-flanged members 2|, see Figure 2 each having a circumferential flange 22 of substantially uniform thickness and walls whose thickness decreases with increasing radial distance from'the center so that uniform torsional shearstress due to torque is maintained through out and substantially uniform bending stress occurs in the plane of flexure. A plurality of diaphragms are secured together to form a unitary structure by fastening the adjacent flanges together by means of screws I8 and lock nuts l9 or other suitable means. The number of diaphragms used in an assembly-may vary from one to several depending upon load conditions.

The diaphragm assemblies l3 and M are connected for torque transmission to the shaft l2 by means of splined flange 23 and long splined flange 24. The splined flanges 23 and 24 are somewhat similar with the-exception that the splined flange 24 has a substantially longer 4 splined portion. The flanges 23 and 24 each have a shoulder portion 25 of substantially the same diameter as the diaphragms 20 and are adapted to besecured to the flange 22 by means of screws I8 and lock-nuts 19 or other suitable means.

In order to provide for greater rigidity of the complete joint as well as to provide safety in the case of a failure of one of the diaphragms 20 the splined flanges 23 and 24 are supported by the members It) and H through means of knuckle "joints 26, arranged in the followingmanner, as

indicated in detail at the left of Figure l. A spherical ball 21 is locked in place on an-axially extending threaded portion 28 of the flanges 23 and 24 by means of a nut 29. The ball 2! is seated in spherical bushings 36 which are positioned in a bearing housing 3| by means of a bearing retainer nut 32. The bearing housing 3| has an-axially' extending threaded portion 33 adapted to be secured to the flange 11 of the members l0 andi by means of a bushing 34 and a nut=35.- In order that the center of gravity of theshaft be-in the plane of rotation the portion 33 has a slight eccentricity with respect to the bearing housing 3| and the outer diameter of the bushing 34 has a slight eccentricity relative to its inner diameter. By rotating the portion 33 of the housing 3| and the bushing 34 relative to each other the center of gravity or balance of the shaft can be shifted into the plane of rotation. In normal operation, the knuckle joint 26 merely wobbles about the ball 21. However, should a failure occur in one of the diaphragms the members l0 and II would be constrained to rotate about the ball.

The quill shaft I2 is a long thin member designed to absorb torque surges by twisting and deforming torsionally. The ends of the shaft l2 terminate in expanded splined portions 36 and 31 adapted to mate with the splined flanges 23 and 24 respectively. The splined portion of the member 24 is substantially greater than that of the portion 31 thus permitting axial movement of the shaft I2 to allow for variations in the distances between the members Ill and II. A retaining ring 38 serves merely to prevent the splined flange 24 from sliding out of mesh while the coupling is being handled or installed.

In order to minimize the possibility of the quill shaft I2 Whipping at high speeds and at the same time retain the torsional deforming characteristics, the shaft I2 is fitted with a pilot bearin 39 which may rotate in a tube 46. the tube 40 is fastened to the splined flange 23 by means of a liner M, having an outward extending section 412, shrunk in the tube 146. Theoutward extending section 42 is secured to the shoulder portion 25 of the splined flange 23 by means of screws 43. The splined portion 36 of the shaft I2 is locked into position with the splined flange 23 by a split ring 44 fitted in a circumferential groove 45 on the splined portion 35 and held against a shoulder 48 of the liner 46 by a spring 1 interposed between shaft l2 and the flange 23 so as to provide a resilient coupling between flange 23 and shaft 12.

The other end of the tube ll} is fitted with a bearing liner is which permits the tube ill to slide and oscillate on the long splined flange 2d. The outer end of the liner 48 is adapted to receive an -ring seal 49 for sealing the lubrication within the tube 4i} and also acts to dampen vibration of the tube fill with the flange 24.

While only one pilot bearing is shown it is un derstood that more than one may be used. The number to be used will depend upon the'design of the shaft and will normally be increased with increased length of the shaft.

In order to protect the diaphrag ns 26 from ex.- ternal damage a cover 58 is provided for the as semblies l3 and M.

In operation the diaphragm assemblies 13 and i4 provide the flexibility necessary to overcome the angularity due to any misalignment and vibration. The knuckle joints 26 provide greater rigidity for the complete coupling without do straying any of its flexible characteristics. Also should one of the diaphragms fail the driving member would merely rotate around the ball of the knuckle joint thus preventing damage as the shaft would be retained by the joint. The tube Ml imparts a desired lateral stiffness to the quill shaft 12 without affecting its torsionally twisting and deforming characteristics. The long splined flange 24 permits the splined portion 37 to slide axially therein to allow for variations in the v(lie-,-

tanoe between the, driving and driven flanges.-

While the flexible coupling has been designated 4 as having a driving and a driven member, it can readily be seen that the coupling can be reversed hence it is immaterial as to which is the driving or driven end.

Although only one embodiment of the invention has been illustrated and described, various ohauges'in the form nd relative arran m of the parts may be made to suit requirements.

What is claimed is: l. A flexible coupling for the transmission of torque'comprising a driving member having a substantially annular flange, a plurality of annular u shaped discs serially connected at their One end of outer edge, means connecting the outer disc at its .outeredge to said annular flange, a driven member. having a substantially annular flange, means connecting the inner disc at its outer edge to said second annular flange, means including a knuckle joint supporting said driven member with said driving member, said knuckle joint having one portion secured to said driving memr nd n h r p on secured to said driven member, and m ans for a justing said knuckle joint to balance said driven member in respect to th axis 01 rotation of sai drivin member, said m an mprising n eccentric portion of aid knuckle joint extendin through and cooperating with an eccentric bushing in sa d driving mem ber and rotative relative thereto.

2. A flexible coupling for the transmission of torque comprising a driving member, a driven member, a flexible diaphragm member for rotatably connecting said driving and driven members, separate means including a knuckle joint for supporting and preventing axial movement of said driven member relative to said driving member, and means for adjusting said knuckle joint for varying the relative position of said driving and driven members, said means including an axially extendin member of said knuckl joint and being eccentric relative thereto, a bushin in said driving member having an outside diameter eccentric relative to the inside diameter and r0- tatable relative to said axially extending member.

HENRY TROEGER. BERNARD W. GOLDBERG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,183,064 Emerson May 16, 1916 1,273,963 Watts July 30, 1918 1,639,480 Baumann Aug. 16, 1927 1,871,227 Smith et al. Aug. 9, 1?:32 1,893,452 Standage Jan. 3, 1933 FOREIGN PATENTS Number Country Date 11,704 Great Britain i905 459,084 Great Britain 1937 564,963 -G1-eat Britain 1944 

